An automobile muffler is a device which lessens the amount of noise emitted by the exhaust of an automobile engine. During operation, the automobile muffler reflects sound waves produced by the automobile engine. These reflected sound waves then cancel out new sound waves generated by the automobile engine in a process known as destructive interference.
One conventional active muffler includes two adjacent (i.e., side-by-side) pipe outlets: a first pipe outlet carrying engine exhaust noise, and a second pipe outlet which is connected to an active secondary noise source. During operation, the active secondary noise source provides active noise cancellation to interfere destructively with the engine exhaust noise.